When a Kiss Is More Than Just a Kiss

"A kiss is just kiss," the old song goes, but not according to a new study that finds kissing helps people assess potential partners and, once in a relationship, keep them around. The study included more than 900 adults who took part in an online questionnaire that asked about the importance of kissing in both short- and long-term relationships. In general, women rated kissing as more important in relationships than men.

Kissing was also rated more important by men and women who viewed themselves as being attractive, or who tended to have more short-term relationships and casual encounters, according to the findings, which appeared Oct. 11 in the journals Archives of Sexual Behavior and Human Nature. Previous studies have shown that women tend to be more selective when initially choosing a partner, as do men and women who are more attractive or have more casual sex partners. Since these are the same groups that tended to value kissing more in their survey responses, it suggests that kissing helps in sizing up potential mates, the Oxford University researchers said. They noted that it has been suggested that kissing may allow people to subconsciously assess a potential partner through taste or smell, thus taking in biological cues for compatibility, genetic fitness or general health.

Previous research also has found that women place greater value on behaviors that strengthen long-term relationships. This survey found that the importance of kissing changed depending on whether people were in a short- or long-term relationship, and that women rated kissing as more important in long-term relationships. This suggests that kissing also plays an important role in maintaining affection and attachment among established couples, the researchers said. "Kissing in human sexual relationships is incredibly prevalent in various forms across just about every society and culture. Kissing is seen in our closest primate relatives -- chimps and bonobos -- but it is much less intense and less commonly used," study author Rafael Wlodarski said in a news release from the journals. "So here's a human courtship behavior which is incredibly widespread and common and, in extent, is quite unique," Wlodarski said. "And we are still not exactly sure why it is so widespread or what purpose it serves." These new findings may provide some answers.